Environmental planning takes advantage of geographic information systems (G
IS) to manage geographic data. GIS are, however, tools which require a grea
t deal of training and programming expertise and, furthermore, have little
support for decision makers during their planning activities. This paper pr
esents WOrkflOw-based spatial Decision Support System (WOODSS) - a software
developed at the University of Campinas, Brazil, to be used in conjunction
with a GIS in order to provide spatial decision support involving environm
ental data. WOODSS was implemented on top of a commercial GIS and tested in
the context of agri-environmental planning activities. WOODSS is centered
on dynamically capturing user interactions with a GIS in real time and docu
menting them by means of scientific workflows. It keeps track of decision p
rocedures, models applied and the choice of parameters in running these mod
els, WOODSS's workflows can be updated on the fly, allowing testing and com
parison of alternative planning strategies. They can, furthermore, be used
as building blocks for the construction of complex decision procedures, sup
porting a divide-and-conquer problem solution style. These workflows intera
ct directly with the GIS, sparing environmental planners and decision maker
s the burden of low-level programming. (C) 1999 Elsevier Science B.V. All r
ights reserved.